Patrick Radden Keefe, a staff writer at The New Yorker, was just about to finish a draft of his third book, Say Nothing: A True Story of Murder and Memory in Northern Ireland, when the Brexit referendum passed in June 2016. Brexit and the surrounding political turmoil immediately threw into relief exactly why Keefe would go on to spend more than four years thinking about Northern Ireland: the contentious border that splits the island into two. Now, it’s a seemingly conflict-free place, but for three decades it was the site of the open, violent struggle that we’ve come to call the Troubles, which tore apart Northern Irish society, and divided cities by religious and political leanings. Thousands of people died, and though the conflict officially ended in 1998, the society is still sensitive to its ramifications.

“What was most striking, for me, spending a lot of time in Belfast,” he said in a recent phone interview, “was how divided the place still is, and the way the peace is still very brittle.” If the United Kingdom leaves without a deal, the Irish border, a former site of bloodshed, could become the new exterior limit of the European Union, complete with checkpoints and customs checks—and it’s unclear what effect this might have. “I think Brexit happened, in part, because policymakers and voters in the U.K. forgot about the Troubles. They forgot about the Irish border,” Keefe said.

Aided by a rich oral history secretly collected by Boston College in the early 2000s, as well as his conversations with previously silent sources, he focuses in on one mystery that lies at the heart of the conflict in Belfast: a set of human bones discovered on a beach in 2003. They are quickly identified as belonging to Jean McConville, a widowed mother of 10 who disappeared from a public-housing complex one night in 1972. But how she wound up there is an unanswered question for another decade.

Jean McConville and her family.

Courtesy of Doubleday.

As Keefe tells the story, McConville’s death is just one piece of a larger story about the Irish Republican Army (I.R.A.), and the young people who were radicalized in the struggle. He spends time understanding the Unknowns, a secret unit of people in their late teens and early twenties who are thought to have committed murders and bombings in the name of the cause. Ultimately, it’s also a story about what it was like to live through the Troubles, and the effects of the trauma on the people who were there.

The book itself focuses on Northern Ireland and this one particular moment in history, but Keefe sees a connection to many other conflicts—even the modern-day political divides in the U.S. “There’s an unpleasant and divisive part of our own history that people just choose not to discuss,” he said. “Electing not to discuss it doesn’t make those scars go away.”

Vanity Fair: The book primarily focuses on two Northern Irish women: a mother who was murdered, and the young woman who might have driven her to her death. How did you come across them, and why did you decide to tell their stories?

Patrick Radden Keefe: In 2013, Dolours Price died, and there was an obituary for her in The New York Times. The obituary described a crazy, dramatic life. She grew up in an I.R.A. family, and, at the beginning of the Troubles, she joins the I.R.A.—but, as she said, she doesn’t want to be making tea or rolling bandages for the men. She is [one of] the first [women] to become a frontline soldier, and leads the bombing mission to London. She gets caught, goes to jail, goes on hunger strike, and faces down with Margaret Thatcher. But [what] the obituary also [alluded to] was that she had been involved in the killing of Jean McConville, this mother of 10, in 1972.

Jean McConville is not a household name in the U.S., but she’s an iconic figure in Northern Ireland, as one of the most famous victims of the Troubles. I wanted to use her disappearance and murder as a way to tell a larger story. Her situation was so extreme—because she’s a mother of 10 and a widow, killing her meant orphaning 10 children.

So from the beginning, from reading that obituary, when I started to think it might be a magazine article, I thought of it as the story of these two women—one the archetypal victim, and the other this very conflicted perpetrator.

On the one hand, it was a 15,000-word magazine article, and it seems as though, “What could you possibly not have said in 15,000 words?” On the other hand, I felt like I’d just scratched the surface.

There were people [to talk to], like Hugh Feeney, who was a really close friend of Dolours, and one of the Unknowns. He was involved in all these secret missions, and I was able to track him down eventually. He’d never really talked to journalists before, and I just felt as though there were so many more doors to knock on.

You have a half-dozen people who, when you meet them in 1972, there’s no daylight between them. They’re all very tight. They’ve got a common cause—young people radicalized in service of a cause they really believe in. But what happens when you check in on them 10 years later, when they’re in their late twenties, early thirties, [and] they get married, they have kids? How do they feel about the things they did at an earlier point? Part of what was interesting was just the differences between these different people and the way they metabolized their own pasts.

Dolours and Marian Price.

Courtesy of Doubleday.

To find that out, you talk to so many people with firsthand experience of the events. You also have the help of oral-history archives, but that doesn’t include everyone. It seems like the most difficult task might have been getting the McConville children to open up. How did you get them to talk to you?

It was hard. One thing that struck me really early on about this story is that you’re dealing with a lot of people—not just the McConville children—who have experienced trauma of a sort that I can scarcely imagine. I’m not an overbearing reporter, in terms of the way I deal with people. I like to try and be as conscientious and gentle as I can. These experiences are just very raw and unprocessed for a lot of people in Northern Ireland, and for the McConvilles in particular. With [middle child] Michael, it took a while to establish his trust and have him talk to me about this stuff. We had some really long and intense conversations.

The McConvilles have been told, again and again, “Don’t cause trouble. Don’t” . . . even when Michael was a kid, right? He was taken by this group from the I.R.A.’s youth wing, and they said, “Don’t go asking what happened to your mother.” The whole process started in the late 1990s, when the McConville kids and other families of the disappeared came out at a time when it was still pretty dangerous to do so and said, “We want the I.R.A. to tell us what happened to our family.” So there is a sense in which I’m grafting onto the process they all bravely initiated.

With the people who were involved in the I.R.A., there was this culture of silence around the work that they did. [But] I think, as humans, most of us have an impulse to tell our own stories. It’s just a very human desire to want to be understood by others.

So, with Hugh Feeney, the other folks that I spoke to, and the people who gave these secret oral histories to Boston College—they felt like their story hadn’t been told. They wanted people to understand the things they did—even the terrible things they did. These people weren’t psychopaths. They planted bombs, they robbed banks, and they went on hunger strike. In some cases, they killed people. But a lot of them think, “I was an ordinary person who became a soldier for a cause that I believed in, and those things that I did seemed justified at the time by my cause.” There’s a really strong desire for people to understand that.

Because of that, you really focus on what it was like to live in Northern Ireland at the time, and what it was like to live through the murders and the hunger strikes, the prison sentences. But at the same time, it’s not a sweeping history, and there are parallels to a lot of different times and places. How did you balance that?

There is a sense in which this book is a murder mystery, and that provides a narrative framework that is intuitive for me as a writer. I care a lot about plot and narrative momentum, and, for me, I never take for granted the attention of my reader. The reader I’m always thinking about is the person you see on the subway who’s got The New Yorker folded over, and pulls it out of their bag to read for two stops in between one errand and another. So they’re reading it in tiny chunks, and it’s always a battle to hold that person’s attention, to get them to keep reading, and not skip to the next article or throw the magazine away.

I’m interested in secret worlds and subcultures and in kind of thorny ethical questions. It wasn’t that I said, “Oh, I want to write a book about the Troubles.” It was that I encountered the story of these people who seemed really compelling, and who clashed in interesting ways. It just so happened that the backdrop was the Troubles, which, it turns out, is a fascinating period of history. The most striking thing for me was just how rapidly it happened. In 1968, things look relatively normal—[at least] as normal had been defined up to that point. By 1972, there are bombs going off every day, and people shooting at each other in the street.

What I’ve tried to do is tell it in an immersive enough way that, if you read it, you’ll get a sense of the extremes to which people and whole societies are willing to go in service of a political idea, and the mania and the carnage that can cause, and how quickly a society can go from the world you recognize to a kind of dystopian hellscape.